Motion pictures typically are produced by serially positioning a large number of still pictures (i.e., "frames") on a medium, such as film, and then utilizing the medium to successively display a set number of the frames during a set time interval. Objects in the frames appear to move because each frame shows a stage of object movement that is slightly changed from that in the immediately preceding frame. Since at least twenty-four frames per second should be displayed to produce satisfactory motion picture quality, a one hour motion picture of satisfactory quality requires about 86,400 separate frames. Accordingly, production of one minute of an animated motion picture (described below) often takes a team of animators between one and three days.
Frames in a motion picture may be created by many known processes. Animation is one known frame creation process in which an animator draws the objects that are displayed in the frame. The objects may be drawn by hand, or by means of computer software on a computer system. Current animation techniques commonly utilize computer software to draw photo-realistic objects that once rendered and used in a motion picture, appear to exist and move in three dimensions (commonly referred to as "3-D animation").
FIG. 1 is a flow chart showing an exemplary process for constructing at least a portion (e.g., one minute) of an animated motion picture on a computer system. The process begins at step 100 in which models of the objects to be animated are constructed on the computer system. This typically is done with known graphical drawing software programs such as, for example, 3D Studio Max.TM. for Windows NT.TM., distributed by Autodesk, Inc. of San Francisco, Calif. Once constructed, the movements of the objects are choreographed, thus producing the geometry data necessary for rendering the moving object (step 102). The process then continues to step 104 in which environmental factors (e.g., spectral effects, coloring, texture, and fog) are added and adjusted with preview-quality rendering equipment. The display quality of preview equipment is relatively poor and thus, used for adjusting environmental factors only. Similar to step 102, step 104 produces additional data (i.e., "environmental data") that is to be used for creating, the individual frames.
The process continues to step 106 in which the environmental data and geometry data are directed to a motion picture production system that produces the motion picture. Among other things, the motion picture production system typically includes a rendering system for rending each of the frames in the motion picture, and a motion picture builder for constructing the motion picture from the rendered frames.
FIG. 2 shows an exemplary process used by the motion picture production system for producing the motion picture. The process begins at step 200 in which the frame data (i.e., the geometry data and the environmental data) is received by the rendering system. The rendering system then utilizes the frame data for rendering each of the frames represented by the received frame data (step 202). Once constructed, each rendered frame is stored in a storage device (discussed below) and identified with a number indicating where the frame is to be positioned in the motion picture (also step 202).
The mathematical computations required to render each frame can be relatively intensive, however, thus causing the rendering step to be very time consuming. For example, it typically takes between about ten minutes and one hour to render a single frame of an animated motion picture. The art has responded to this problem by dividing the processing required by the rendering step between a plurality of separate rendering units that each have an independent processor. This frame rendering technique commonly is referred to as "distributive frame rendering." Accordingly, the rendering units each are assigned a certain number of frames for processing, therefore decreasing the total time required to render each of the frames in the motion picture.
Once the frames are rendered, an animator (or other person) must manually locate each rendered frame in the storage device (step 204). Since the storage device can include numerous disk drives, directories, and additional externally connected storage devices, this step also can be quite time consuming. At step 206, each frame must be manually moved by the animator into a single directory in the storage device for access by the motion picture builder application program. Once in the single directory, the motion picture builder may arrange the frames in a preconfigured order to form the motion picture (step 208).
Although necessary, each of the above noted manual steps is very time consuming, thus delaying the production of the motion picture and increasing its ultimate production cost. Moreover, the noted prior art processes does not enable the motion picture builder to build the motion picture until each of the frames in the motion picture are rendered. A delay by a single frame therefore can delay the production of the entire motion picture.
Accordingly, it would be desirable to provide a method and apparatus that eliminates the prior noted inefficiencies in the motion picture production process.